Grade 10 SCIENCE | Gay-Lussac's Law
Summary
TLDRThe video script discusses Gay-Lussac's Law, which describes the direct proportionality between pressure and temperature for a given amount of gas at constant volume. The presenter explains the law's formula, ( P1/T1 = P2/T2 ), where P stands for pressure and T for temperature in Kelvin. The importance of using consistent units and converting Celsius to Kelvin for temperature measurements is highlighted. Two problems are solved using the law: one involving a gas cylinder with varying pressures and temperatures, and another concerning the pressure change in a helium-filled balloon with an increase in temperature. The video aims to help viewers understand the relationship between pressure and temperature, emphasizing the need for step-by-step problem-solving and accurate unit conversion.
Takeaways
- 📚 Gay-Lussac's Law is not part of the original video series but was requested by viewers, showing the relationship between pressure and temperature.
- 🔗 The law is similar to Charles' Law and is often discussed alongside Boyle's Law, with a link provided for further review.
- 📐 The general form of Gay-Lussac's Law is p1/t1 = p2/t2, where p represents pressure and t represents temperature.
- 📉 Subscripts 1 and 2 refer to the initial and final states of a system, which are crucial for problem-solving.
- 🔍 Units for pressure can vary (e.g., atmospheres, mmHg, kPa), but temperature must be in Kelvin, converting from Celsius if necessary.
- ⚖️ Direct proportionality means that if temperature increases, pressure increases, and vice versa, assuming volume and the amount of substance are constant.
- ✅ The importance of understanding the relationships between pressure and temperature is emphasized for accurate problem-solving.
- 🔢 Problem-solving involves converting temperatures to Kelvin when given in Celsius, and using the correct formula for Gay-Lussac's Law.
- 🌡️ Example problem: A gas cylinder with an initial pressure and temperature is used to find the new temperature at a different pressure, requiring unit conversion and equation manipulation.
- 🎈 Another example involves a mylar balloon with helium gas, where the pressure change is calculated given a temperature increase from 22°C to 45°C.
- 📈 The expected outcome of the second problem is a pressure greater than the initial 107 kilopascals due to the direct relationship between temperature and pressure.
- 📝 The final pressure for the helium balloon is calculated to be 115 kilopascals, demonstrating the application of Gay-Lussac's Law in real-world scenarios.
Q & A
What is Gay-Lussac's Law?
-Gay-Lussac's Law relates the pressure and temperature of a gas when the volume and the amount of gas are held constant. It states that the pressure of a gas is directly proportional to its temperature in Kelvin, given by the formula p1/T1 = p2/T2, where p is pressure and T is temperature.
How is Gay-Lussac's Law similar to Charles's Law?
-Both Gay-Lussac's Law and Charles's Law describe the relationship between pressure and temperature in a gas. However, Charles's Law specifically deals with the volume and temperature relationship at constant pressure, while Gay-Lussac's Law focuses on the pressure and temperature relationship at constant volume.
What are the units typically used for pressure in problems related to Gay-Lussac's Law?
-Pressure can be expressed in various units such as atmospheres, millibars, torr (millimeter mercury), or kilopascals. The specific unit used is not critical as long as the problem and the answer use the same unit.
How do you convert Celsius to Kelvin?
-To convert a temperature from Celsius to Kelvin, you add 273 to the Celsius temperature. For example, 25 degrees Celsius is equivalent to 298 Kelvin (25 + 273 = 298 K).
What does it mean for pressure and temperature to be directly proportional?
-When pressure and temperature are directly proportional, it means that if the temperature increases, the pressure also increases, and if the temperature decreases, the pressure decreases as well. This relationship holds true as long as the volume and the amount of gas are constant.
What is the general form of the equation used in Gay-Lussac's Law?
-The general form of the equation used in Gay-Lussac's Law is p1/T1 = p2/T2, where p1 and p2 are the initial and final pressures, and T1 and T2 are the initial and final temperatures in Kelvin.
How do you solve for the final temperature in the given problem with a gas cylinder?
-To solve for the final temperature, you first convert the initial temperature from Celsius to Kelvin, then use the initial pressure and the final pressure in the Gay-Lussac's Law equation to find the final temperature in Kelvin. After that, you convert the final temperature back to Celsius.
What is the expected change in pressure when the temperature of a gas increases, according to the video?
-When the temperature of a gas increases, the pressure of the gas is also expected to increase, as they are directly proportional to each other.
What is the relationship between the initial and final states in the given helium balloon problem?
-The relationship between the initial and final states in the helium balloon problem is given by the Gay-Lussac's Law equation, where the initial pressure and temperature are known, and the final pressure is solved for after the temperature increases.
How do you calculate the final pressure of helium in the balloon when the temperature changes?
-You use the initial pressure and temperature to find the final pressure using the Gay-Lussac's Law equation. After substituting the known values into the equation, you solve for the final pressure (p2) by cross-multiplying and simplifying the equation.
What is the final pressure of the helium in the balloon when the temperature changes from 22 degrees Celsius to 45 degrees Celsius?
-The final pressure of the helium in the balloon is 115 kilopascals, calculated using the Gay-Lussac's Law equation with the given initial and final temperatures converted to Kelvin.
Outlines
🔬 Introduction to Gay-Lussac's Law
The first paragraph introduces the topic of Gay-Lussac's Law, which describes the relationship between pressure and temperature in a gas. The video aims to clarify this concept, noting its similarity to Charles' Law and its relevance alongside Boyle's Law. The general form of the law is presented as p1/t1 = p2/t2, where p represents pressure and t represents temperature. The importance of using the correct units for pressure and temperature is emphasized, with a reminder to convert Celsius temperatures to Kelvin by adding 273. The direct proportionality between pressure and temperature is highlighted, assuming the volume and the amount of gas remain constant.
📚 Applying Gay-Lussac's Law to a Problem
The second paragraph delves into applying Gay-Lussac's Law to a specific problem. It involves a gas cylinder with an initial pressure and temperature that is subjected to a change in pressure, with the goal of finding the new temperature. The process includes converting the initial temperature from Celsius to Kelvin, setting up the equation according to the law, and solving for the final temperature. The paragraph emphasizes the need for careful unit conversion and equation manipulation, and it provides a step-by-step approach to ensure accuracy in the calculation.
🎈 Gay-Lussac's Law and Helium Balloon Pressure
The third paragraph presents a real-world scenario involving a mylar balloon filled with helium, where the pressure changes with an increase in temperature. The problem involves calculating the new pressure of the helium in the balloon when the temperature rises from 22 degrees Celsius to 45 degrees Celsius. The given initial pressure and temperature are converted to Kelvin, and the law's formula is applied to find the final pressure. The calculation process is detailed, leading to the conclusion that the pressure increases from 107 kilopascals to 115 kilopascals, demonstrating the direct relationship between temperature and pressure.
📉 Conclusion and Engagement Invitation
The final paragraph wraps up the discussion by summarizing the key points covered in the video and encouraging viewers to apply the knowledge to understand their modules better. The presenter invites the audience to like, subscribe, and share the video with others. It ends with a friendly farewell, looking forward to the next interaction.
Mindmap
Keywords
💡Gay-Lussac's Law
💡Pressure
💡Temperature
💡Charles' Law
💡Boyle's Law
💡Initial State
💡Final State
💡Directly Proportional
💡Kelvin
💡Conversion Factor
💡Problem Solving
Highlights
Gay-Lussac's Law discusses the relationship between pressure and temperature in a gas.
The formula for Gay-Lussac's Law is p1/t1 = p2/t2, where p represents pressure and t represents temperature.
Subscripts 1 and 2 in the formula refer to the initial and final states of the gas.
Pressure must be expressed in units of pressure, and temperature must be in Kelvin.
Conversion from Celsius to Kelvin involves adding 273 to the Celsius temperature.
Pressure and temperature are directly proportional as long as the volume and the amount of substance are constant.
If temperature increases, pressure increases, and if temperature decreases, pressure decreases.
The video provides a step-by-step solution to a problem involving a gas cylinder with varying pressure and temperature.
For problems, it's essential to identify initial and final states and follow the given equation.
The video demonstrates converting temperatures from Celsius to Kelvin and back for calculations.
The second problem involves a mylar balloon filled with helium and its pressure change with temperature.
An increase in temperature from 22 to 45 degrees Celsius is expected to result in a higher pressure.
The final calculated pressure of helium in the balloon is 115 kilopascals after a temperature change.
The video emphasizes the importance of step-by-step calculations and understanding the relationships between variables.
Gay-Lussac's Law is similar to Charles's Law, and understanding one can facilitate understanding of the other.
The video includes a link to a discussion about Charles's Law for further understanding.
The video concludes with an encouragement to like, subscribe, and share the content for better comprehension.
Transcripts
hello students for today's video i will
be discussing
a little about
what we call gay lussac's law
so by the way um this is not included in
the videos that i have originally in my
youtube account
because this is not part of the
milks
young recent milk snack and judu
pandemic
but then there are some people who
requested
me to discuss gay losers law
which as you can see now it shows
pressure and temperature relationship so
later on i will explain you manga manga
about the massive pressure bottom as a
temperature but then this law is very
much similar to charles law so
an audio discussion about charles law i
have placed the link
above so you can review it it is
combined with boyle's laura say union
so
let's start so what is the general form
for gay loose law
it is very similar with charles law
so
it relates pressure and temperature
using the formula
p1
over t1
is equal to
p2 over t2 where of course
p would stand for pressure
and t would stand for your temperature
what are the subscripts what do they
mean
when we say number one usually this is
referring
to the initial state so you'll start
all right and then
final
or you end we have to analyze the
problem
initial and final for you to be able to
answer a problem successfully you need
to be able to identify the correct given
and make sure that you follow in the tao
natin agresa given
required equation solution answer unless
you are very confident with your maths
skills by the mushander
but if you're not confident then you
have to do it step by step so going back
to our equation
we have p1 over t1 is equal to p2 over
t2
pressure
uh must be expressed in
of course pressure units but then we are
not really strict about the units
because
the problem uses atmospheres
automatic atmospheres narinyon is
pressure
so my usual
wedding atmospheres
wedding
tour wedding millimeter mercury
wedding kilo pascals
hindi time unless the problem states
answer monarch express at a particular
unit so temperature detail pet
because
your temperature must be in
kelvin
there are some cases when your
temperature given is in degree celsius
so you have to convert that into kelvin
now what is our conversion factor
kelvin temperature can be obtained by
just adding
273 to degrees celsius
some college books they use 273.15
pero right now in our discussion we will
just be using 273.
it's very important that you convert the
temperature to kelvin
kung hindi
kelvin
all right
relationships
according to
gay
pressure
and temperature are
directly proportional as long as your
volume and your amount of substance
they are
constant
so what do we mean by directly
proportional
pressure temperature you will be
arriving at a graph
like this
it means that if you increase the
temperature
your pressure must increase
similarly if temperature decreases your
pressure also decreases
so why am i emphasizing these
relationships because if you are doing a
quick calculation you can always go back
to this
relationships
are pressure
temperature
that means there is something wrong with
your
solving so
let's start with our problems i will be
discussing here two problems only
let me
write the grace
given
required
equation
and then solution and answer
in
let's read the problem a cylinder of gas
has a pressure of 4.40 atmospheres at 25
degrees celsius
at what temperature in degree celsius
will it reach a pressure of 6.50
atmospheres
if we analyze the problem
why to say you have the temperature in
degree celsius
so naturally if you are listening to
what i have said a while ago you have to
convert this to kelvin first
and then
kelvin and then you have to convert it
back to
degree celsius
let's do it step by step
given monetary
a cylinder of gas has a pressure of 4.40
atmospheres so
that would be your p1
at temperature of
25 degrees celsius
we add 270
then what do we get
we will be getting 298
kelvin
and then
our final pressure is this
6.50
atmosphere
we are looking for
a temperature but make sure it must be
in degree celsius
let's write the equation here p1 over t1
is equal to p2 over t2
um actually
young manga problems
now related uh
charles law and gaylo saxlow major three
kisha kapagnawawwala
temperature kasena babasha you have to
do a lot of rearrangements now if you
are not really used to deriving
equations
so
for some of my students what i advise is
to flip the equation
numerator so in our case i'm missing
nathan is t2
okay so
not in pueden
equation
t1 over p1 is equal to t2 over
p2
just don't forget that what you do on
the left you must also do on the right
para
indicator
and so nice nothing other equation let's
write the solution what is t1 that would
be 298
kelvin
over the p1 that's 440
atmospheres over t2
equals
t2 over
6.50
atmospheres
6.50
atmospheres both sides
therefore our t2 would be
298 kelvin
times 6.50
atmospheres over
4.40
atmospheres
atmospheres
and let's use our
calculator
so t2 is equal to
440
point
23
kelvin
but wait there's more sabinatin at what
temperature in
degree celsius
the given current temperature in kelvin
kela and malek some degree celsius to do
that we subtract 273
and we will be getting
167 point
[Music]
degrees celsius
and that would be our
answer
quick analysis la sabina
directly proportional to pressure at sea
temperature soda
pressure
temperature
okay
let's move to
our
next
problem
mylar balloon is filled with helium gas
to a pressure of 107 kilopascals
when the temperature is 22 degrees
celsius
if the temperature changes to 45 degree
celsius what will be the pressure of the
helium in the balloon
so again the temperature increased from
22 to 45 so we will be expecting our
answer to
be greater than 107 kilo
pascals
let me write the given parts of gresa
pressure one
is equal to 107
kilopascals
t1 is 22 degrees celsius
if we add 273 there that is
298 kelvin
and t2 is 45 degrees celsius we do the
same add 273
that would be
318
kelvin
oops 22
plus 273 is
i mistaken this is 295 kelvin
and 45 plus 273 is still 318.
so anohina hanap
pressure of the helium
in the balloon p2
our formula for galux law is p1 over t1
is equal to p
2 over t2
p2 is already in the numerator so we
don't need to
flip the equation we simply substitute
so 107 kilopascals over
295 kelvin
is equal to
p2
times
318
kelvin
to simplify we multiply both sides by
318 kelvin
so therefore our p2 is equal to 107
kilopascals
times
318 kelvin
divided by
295
kelvin
so our answer is 115
kilo
pascals
so there you go that's all for our short
discussion today i hope this has helped
you
understand your modules better and
please like and subscribe my videos if
you have time or you can also share that
to your classmates or friends
so see you next time bye
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